San Francisco Mayor Edwin Lee signed a document Wednesday formalizing the city's acceptance of a statue that symbolizes Korean and other Asian women forced into wartime brothels for the Japanese military, city officials said, prompting the mayor of its sister-city Osaka to decide on dissolution of their affiliation.

The Japanese government had called on Lee not to accept the statue after the U.S. city's council passed the motion last week. Following Lee's approval, Osaka Mayor Hirofumi Yoshimura said he plans to complete procedures to dissolve the sister-city affiliation with San Francisco in December.

"My understanding is that sister-city ties are based on a strong relationship of trust, so I believe our relationship of trust has ended," Yoshimura said in a statement.

The statue -- of three Chinese, Korean and Filipino girls standing hand in hand -- was set up by a local private organization as a memorial honoring the so-called "comfort women" in San Francisco's Chinatown area in September.

Other comfort women memorials in the United States include a statue in Glendale, southern California, and a memorial in the state of Virginia.

In 2015, Japan and South Korea reached a landmark deal to "finally and irreversibly" resolve the comfort women issue, with Japan disbursing 1 billion yen ($8.9 million) last year to a South Korean fund to provide support to former comfort women and their families.

But the administration of new South Korean President Moon Jae In argues that "the majority of the country's public do not approve of the comfort women agreement" on an emotional level.

Osaka and San Francisco formed sister-city ties in 1957, launching high-school student exchanges and other programs.

The Osaka mayor had warned that if San Francisco accepted the statue, it would impair their relationship of trust.

Japanese Prime Minister Shinzo Abe earlier said it was "extremely regrettable" that San Francisco's assembly had accepted the statue.